Sound communication is very important for information exchange and emotional expression. With the prosperous development of multimedia industry, various sound recording apparatuses, such as recording pens, recorders and recording rooms, are progressing to record the sound field as truly as possible. Simultaneously, various sound playing devices, such as household speakers, vehicular audio systems, theater surround audio systems, and earphones, are required to present higher and higher fidelity. Therefore, high-end sound field recording and replaying technology is always the target the related manufacturers are eager to achieve.
A Chinese patent publication No. CN101001485 disclosed a finite-sound source and multi-channel sound field system, which comprises a microphone array recording M-channel audio signals and detecting the characteristics of the sound field; an audio frequency collection subsystem transforming the moduli of audio signals in different channels, packaging the audio data, and labeling the channels and timings; a server processing the audio data of the microphones, separating and processing the sound sources, compressing and storing data, mixing the data of the sound sources and transforming the mixed data into the output data of N pieces of speakers according to the M-channel sound source information and the characteristics of the reconstructed sound field; an audio restoring subsystem arranging the data of different sound sources into multi-channel analog signals and synchronizing the multi-channel speakers; and a speaker array playing the N-channel audio signals. Thereby, the prior art separates and collects sound source signals, dynamically matches M and N in a weighted way, omnidirectionally and precisely reproduces the original sound field, reduces the distortion of sound field phases, and avoids the interference and other distortions in processing, amplifying and playing signals.
However, the abovementioned finite-sound source and multi-channel sound field system needs a particle filter to separate noise and interference and has to transform audio data in recording signals, which results in complicated processes. Further, the conventional technology needs to adjust the volumes of speakers in replaying signals, which makes it likely to lose fidelity and have a smaller sweet spot. Therefore, the conventional technology still has room to improve.